2SCIENTIFIC NOTATIONScientists often have to work with very large or very small numbers.It’s a system that uses a simpler form of these numbers.In scientific notation, all numbers are written in the form:a x 10nIn this form, a can be greater than or equal to 1 but less than 10 and n can be any value.
3SCIENTIFIC NOTATIONFor large numbers, move the decimal place to the left.The number of times you move the decimal point to the left will be equal to the exponent on the base 10.Example: (the exponent will be +3)1.5 x 103For small numbers, move the decimal place to the right.Note, the exponent on the base is negative.Example: (the exponent will be -2)5.05 x 10-2
4SCIENTIFIC NOTATIONOn a scientific calculator, enter using the following sequence:EXP or EE +/- 2Practice converting the numbers below from standard form into scientific notation8,200,000 = ______________________50,880,000,000,000 = ______________= ________________________= __________________8.2 x 1065.088 x 10131.2 x 10-44.58 x 10-9
6QUESTION NOW ... what is the length of the screw? A ruler marked in millimeters can generally make a much more precise measurement than a ruler marked in centimeters.
7SIGNIFICANT DIGITSEvery experiment involves some uncertainty in measurement.Significant digits are CERTAIN digits (considered accurate) plus one UNCERTAIN (estimated) digit used in the measurement.For example, the length of the screw:5.N Vs 5.1NThe precision of a measurement can be shown by the number of significant digits in the value.
8SIGNIFICANT DIGITS RULES & EXAMPLES Any non-zero digit is significant.Ex has four significant digits.Zeros used to space a number to the right of a decimal point are not significant.Leading zeros are not significant (to the left of non-zero digits)Ex has only three significant digits.Trailing zeros, to the right of any non-zero digits, are not significant (when there is no decimal).Ex. 74,000 has only two significant digits.All other zeros are significant.Ex has 4 significant digits.
9CALCULATING WITH SIGNIFICANT DIGITS ROUNDING RULE:Rounding after the last significant digit< Leave it> Round up= Round to the even numberExample: round numbers to 4 significant figures12.36412.36612.365
10CALCULATING WITH SIGNIFICANT DIGITS RULE:In any calculation, the number of significant digits in the answer cannot be greater than the number of significant digits of any measured value.For example, suppose you do the following calculation:5.73 x = In this situation, the second measurement has the fewest significant digits. Therefore, the answer must also have just two significant digits and should be reported as 12.
11CERTAINTY RULE FOR MULTIPLICATION & DIVISION The answer has the same number of digits as the least significant figure (regardless of placement).Ex x 0.56 =Ex x 4.01 =Ex / 40. == 43= 10.2= 13
12PRECISION RULE FOR ADDITION & SUBTRACTION The answer has the same number of decimal places as the least number in the question.Ex ==241.9
13METRIC CONVERSIONS Metric system: The system of units used by most scientists.Also known as System International (SI) units.In the metric system, different units for the same quantity are related to one another by prefixes.Each prefix represents a multiple of 10.
14METRIC CONVERSIONS All the conversions are multiples of 10. Converting from one unit to another, such as from meters to centimeters, simply involves shifting the decimal point to the left or right. Example:12.56 meters = 1,256 centimeters = kilometers. Follow the diagram in the handout.
15METRIC CONVERSIONS Tips for solving unit conversion problems: Always be aware of the unit you start with and the unit you have been asked for.When converting any type of measures:To convert from a larger to smaller metric unit you always multiplyTo convert from a smaller to larger unit you always divide
16METRIC CONVERSIONSThis is the metric conversion stair chart. You basically take a place value chart turn it sideways and expand it so it looks like stairs.The Latin prefixes literally mean the number indicated. Meter, liter or gram can be used interchangeably.